Download A New Functional Framework for a Sound System for Realtime Flight Simulation We will show a new sound framework and concept for realistic flight simulation. Dealing with a highly complex network of mechanical systems that act as physical sound sources the main focus is on a fully modular and extensible/scalable design. The prototype we developed is part of a fully functional Full Flight Simulator for Pilot Training.
Download A Framework for Sonification of Vicon Motion Capture Data This paper describes experiments on sonifying data obtained using the VICON motion capture system. The main goal is to build the necessary infrastructure in order to be able to map motion parameters of the human body to sound. For sonification the following three software frameworks were used: Marsyas, traditionally used for music information retrieval with audio analysis and synthesis, CHUCK, an on-the-fly real-time synthesis language, and Synthesis Toolkit (STK), a toolkit for sound synthesis that includes many physical models of instruments and sounds. An interesting possibility is the use of motion capture data to control parameters of digital audio effects. In order to experiment with the system, different types of motion data were collected. These include traditional performance on musical instruments, acting out emotions as well as data from individuals having impairments in sensor motor coordination. Rhythmic motion (i.e. walking) although complex, can be highly periodic and maps quite naturally to sound. We hope that this work will eventually assist patients in identifying and correcting problems related to motor coordination through sound.
Download Implementation of Arbitrary Linear Sound Synthesis Algorithms by Digital Wave Guide Structures The Digital Wave Guide (DWG) method is one of the most popular techniques for digital sound synthesis via physical modeling. Due to the inherent solution of the wave equation by the structure of the DWG method, it provides a highly efficient algorithm for typical physical modeling problems. In this paper it will be shown, that it is possible to use this efficient structure for any existing linear sound synthesis algorithm. By a consequent description of discrete implementations with State Space Structures (SSSs), suitable linear state space transformations can be used to achieve the typical DWG structure from any given system. The proposed approach is demonstrated with two case studies, where a modal solution achieved with the Functional Transformation Method (FTM) is transformed to a DWG implementation. In the first example the solution of the lossless wave equation is transformed to a DWG structure, yielding an arbitrary size fractional delay filter. In another example a more elaborated model with dispersion and damping terms is transformed, resulting in a DWG model with parameter morphing features.
Download Segregation of Two Simultaneously Arriving Narrowband Noise Signals as a Function of Spatial and Frequency Separation The present paper details a set of subjective measurements that were carried out in order to investigate the perceptual fusion and segregation of two simultaneously presented ERB-bandlimited noise samples as a function of their frequency separation and difference in the direction of arrival. This research was motivated by the desire to gain insight to virtual source technology in multichannel listening and virtual acoustics applications. The segregation threshold was measured in three different spatial configurations, namely with a 0◦ , a 22.5◦ , or a 45◦ azimuth separation between the two noise signals. The tests were arranged so that the subjects adjusted the frequency gap between the two noise bands until they in their opinion were at the threshold of hearing two separate sounds. The results indicate that the frequency separation threshold is increased above approximately 1.5 kHz. The effect of angle separation between ERB-bands was less significant. It is therefore assumed that the results can be accounted by the loss of accuracy in the neural analysis of the complex stimulus waveform fine structure. The results are also relatively divergent between subjects. This is believed to indicate that sound fusion is an individual concept and partly utilizes higher-level processing.
Download CMOS Implementation of an Adaptive Noise Canceller into a Subband Filter In recent years the demand for mobile communication has increased rapidly. While in the early years of mobile phones battery life was one of the main concerns for developers speech quality is now becoming one of the most important factors in the development of the next generation of mobile phones. This paper describes the CMOS implementation of an adaptive noise canceller (ANC) into a subband filter. The ANC-Subband filter is able to reduce noise components of real speech without prior knowledge of the noise properties. It is predestined to be used in mobile devices and therefore, uses a very low clock frequency resulting in a small power consumption. This low power consumption combined with its small physical size enables the circuit also be used in hearing aids to efficiently reduce noise contained in the speech signal.
Download Audio Rendering System Design for an Object Oriented Audio Visual Human Perception Assessment Tool The cognitive processes behind human bimodal (audio visual) perception are not well understood. This contribution presents an approach to reach a deeper understanding by means of subjective assessments of (interactive) audio visual applications. A tool developed for performing these assessments is introduced, and the audio rendering system design of that tool is explained: its modular character, the signal processing flow as well as the possible reproduction setups are discussed. Finally, an example for the assessment of geometrically based room simulation and preliminary test results are given.
Download FEAPI: a low level feature extraction plugin API This paper presents FEAPI, an easy-to-use platform-independent plugin application programming interface (API) for the extraction of low level features from audio in PCM format in the context of music information retrieval software. The need for and advantages of using an open and well-defined plugin interface are outlined in this paper and an overview of the API itself and its usage is given.
Download Generalised Prior Subspace Analysis for Polyphonic Pitch Transcription A reformulation of Prior Subspace Analysis (PSA) is presented, which restates the problem as that of fitting an undercomplete signal dictionary to a spectrogram. Further, a generalization of PSA is derived which allows the transcription of polyphonic pitched instruments. This involves the translation of a single frequency prior subspace of a note to approximate other notes, overcoming the problem of needing a separate basis function for each note played by an instrument. Examples are then demonstrated which show the utility of the generalised PSA algorithm for the purposes of polyphonic pitch transcription.
Download Polyphonic music analysis by signal processing and support vector machines In this paper an original system for the analysis of harmony and polyphonic music is introduced. The system is based on signal processing and machine learning. A new multi-resolution, fast analysis method is conceived to extract time-frequency energy spectrum at the signal processing stage, while support vector machine is used as machine learning technology. Aiming at the analysis of rather general audio content, experiments are made on a huge set of recorded samples, using 19 music instruments combined together or alone, with different polyphony. Experimental results show that fundamental frequencies are detected with a remarkable success ratio and that the method can provide excellent results in general cases.